1. Field of the Invention
The present invention relates to a LiBr aqueous solution injection apparatus of a freezer system, and more particularly, it relates to improvements therein for securing the LiBr aqueous solution injection apparatus upon a sub-injection pipe.
2. Description of the Conventional Art
A LiBr aqueous solution injection apparatus of a horizontal suction type freezer is a very useful apparatus.
As shown in FIG. 1, reference numeral 1 denotes an absorber located between a regenerator 6 and a condenser 7. In the absorber 1, horizontal heat transfer tubes 2 are provided with a predetermined space from an intermediate portion of the absorber 1, respectively. A LiBr aqueous injection apparatus 3 is provided at an upper part of the horizontal heat transfer tube 2. Also, an evaporator 4 having a heater 4a is downwardly spaced from the horizontal heat transfer tube 2.
A collection tank 5 is connected to the lower part of the absorber 1 in order to collect the LiBr aqueous solution discharged from the LiBr aqueous injection apparatus 3.
In order to regenerate the LiBr solution discharged from the collection tank 5, a regenerator 6 is connected to the collection tank 5 via pump 8 and valve 8a. The regenerator 6 includes a cooling coil 9 for controlling an inner temperature of the regenerator 6 and a heating means 9a.
The regenerator 6 is connected to a condenser 7 through a valve 8a. The condenser 7 is also connected to the evaporator 4 via pump 8 and valve 8a. A cooling coil 9 is provided within an upper part of the condenser 7.
In order to accomplish heat exchange with cooling water which flows in the horizontal heat transfer tube 2 by heat of vaporization, it is necessary to provide an aqueous solution membrane on a surface of the horizontal heat transfer tube 2 by discharging the LiBr aqueous solution on the horizontal heat transfer tube 2.
As shown in FIG. 2A, a main injection pipe 11 is integrally connected to a nozzle 12. The main injection pipe 11 and nozzle 12 are spaced at a certain distance from the horizontal heat transfer tubes 2. The LiBr aqueous solution discharged via pump 8 and valves 8a from the regenerator 6 is distributed in a regular amount via an injection hole 12a of the nozzle 12 as shown in FIG. 2C.
When a pressure of the LiBr aqueous solution contained in the nozzle 12 reaches about 3 Kg/cm2, it is injected at angles of 60 to 80 degrees via the injection hole 12a of the nozzle 12 as shown in FIGS. 2B and 2C.
Since the injected LiBr aqueous solution contact the upper surface of the horizontal heat transfer tube 2, it can be absorbed with a refrigerating vapor due to the LiBr aqueous solution membrane 2b formed on the surface of the horizontal heat transfer 2. At this time, it is accomplished with the heat exchange from the cooling water of the horizontal heat transfer tube 2.
FIG. 3 shows a tray injection type LiBr aqueous solution injection apparatus.
As shown in FIGS. 3A and 3B, in the LiBr aqueous solution injection apparatus, the LiBr aqueous solution discharged from absorber 1 by operating a pump 8 from regenerator 6 (refer to FIG. 1) which is filled with a main injection pipe 11a. Since a plurality of projections 11c are formed with the main injection pipe 11a, the LiBr aqueous solution flows downwards via slit grooves or slots 11b as shown in FIGS. 3B and 3C. That is, the LiBr aqueous solution is discharged from the horizontal heat transfer tubes 2 via the slit grooves 11b.
After the LiBr aqueous solution is discharged from the slit grooves 11b, the actuating relation of the LiBr aqueous solution in the tray injection type LiBr aqueous solution injection apparatus, is similar to that of the nozzle injection type LiBr aqueous solution injection apparatus.
The above-mentioned LiBr aqueous solution injection apparatus poses the following problems.
Although the conventional nozzle injection type LiBr aqueous solution injection apparatus discharges the aqueous solution equally among all to the upper surfaces of the horizontal heat transfer tubes, pressure loss is greatly increased due to the small size of the injection holes. Thus, it is economically disadvantages due to the required continuous increase of pumping power of the pumps.
On the other hand, since the LiBr aqueous solution is run down through the slit grooves in the tray injection type LiBr aqueous solution injection apparatus, the LiBr aqueous solution having a high surface tension, is not equally divided into the horizontal heat transfer tubes. Also, the LiBr aqueous solution is not formed with a complete and uniformly thin membrane on the horizontal heat transfer tubes because the LiBr aqueous solution tends to form a thick-stem type membrane.
Consequently, a heat transfer efficiency of the tray injection type LiBr aqueous solution injection apparatus is lower than the LiBr aqueous solution injection apparatus having a nozzle and also the total efficiency, of the freezer decreases.